Karl b



KL 8-. SHULZQ FU8E PLUG.

APPLICATION FILED FEB. 12, 1919.

Patented Nov. 4, 1919.

KARL B. SHULZ, OF NEW YORK, N. Y.

FUSE-PLUG.

Specification of Letters Patent.

Patented Nov. 4, 1919.

Application filed February 12, 1919. Serial No. 276,560.

To all whom it may concern: a

}Be it known that I, KARL B. SHULZ, born in Danzig, Prussia, and now residing at 1101 Westchester avenue New York, county of New York, and tate of New York, have invented certain new and useful Improvements in Fuse-Plugs, fully described and represented in the following specification and the accompanying drawin s, forming a part of the same. I

he present invention relates to a fuse plug having an insulating body with a contact shell uponone end, an interior socket wholly inclosing the fuse wire, a connector extending from the shellthrough the wall of the body into,the socket, and a central contact sorew extended through the end of the body into the socket.

The improvements consist of special con structions for the parts which connect the connector with the central contact screw.

The invention will be understood by reference to the annexed drawing, in whic Figure 1' is an outside view of the entire fuse plug; Fig. 2 is a lon itudinal section of the insulating body, at t e center line of the plug, with the arts mounted-therein; Fig. 3 is a longitudlnal section of the connector with its clamp screw and elongated nut; Fig. 4 shows the larger end of the fuse plug with the cap removed; Fig.5 is a .sec-

' tion on line 5-5 in Fig. 2; Fig. 6 is a section on line 66 in Fig. 2; Fig. 7 is a perspective view of the nut; Fig. 8 a perspective view of the bushing; and Flg. 9 aperspective view of the washer for the bush- The insulating body is made of any suitable material and is shown with reduced end a having a threaded 'shell I) secured thereon to make contact with the wall of the plug-receiver or socket.

The body is formed'with enlarged head.

a to permit the formation of a recess 0 large enough to insert the fingers to apply the fuse wire d. A socket c is extended from the recess toward the reduced end of the body, through which end a bushing f is inserted to form a fixed contact-bearing for one end of the fuse wired.

The outer end of the bushing is shown with flange f and the inner end is inserted through a washer g and riveted or clenched over the washer in the bottom of the socket 0, thus locking the bushing permanently in place, and forming on the bottom of the socket a fixed electrical contact for the fuse Wire (it A central contact screw h is inserted through the stationary bushing into a nut eby which the screw presses a loop of the fuse wire against the bushing. The fuse wire requires a connection from the center contact to the contact shell I) and this has been commonl effected by a stri of sheetmetal solder'e to the shell an extended into the interior of the plug by a rightangle bend which formed a very inadequate support for the fuse wire because it afforded such a very thin threaded hole to engage the clamping screw.

This defective feature is corrected in the present construction by making the connector of a metallic block is having a thickened and elongated head k in which a long threaded hole is formed to engage the clamp screw j as shown in Fig. 3. This construction prevents the screw threads from stripping, as often happens with a ver thin nut.

he connector blockjc is embedded or lies in a groove z in the wall of the bod extending from the shell I) to the interior of the recess c. The thin end of this connector is soldered to the shell at n and thus makes a connection between the same and the interior of the recess a, in which the located.

The fuse wire (1 is loo ed around the screw j and clamped there y, and its opposite or inner end looped or bent .into an eye to embrace the center contact screw 71.. This eye lies upon the inner end of the bushing, and when the nut is pressed toward the bushing by the screw, it clamps the inner end of the fuse wire between two conducting surfaces so as to maintain an excellent contact therewith. 1

To facilitate the application of the fuse wire to the nut, the side ofthe nut opposite tothat next the connector is formed with a groove Z, and the adjacent wall of the socket 0 is formed with a corresponding groove Z. This permits the free passage of the nut past the wire when the latter is seated on the bushing.

In applying a new fuse when the fuse wireis blown out, the new one is applied head 70' is which is bent away from the connector to permit such insertion of the nut; and the central screw it is then screwed into the nut and the fuse end clamped tightly upon the bushing.

The socket is made square and a little larger than the square nut e to hold the nut from turning, and is extended from the fixed l gil washer 9 all the way to the recess so as to guide the nut exactly into engagement with the screw it when it is dropped into the socket. The flat sides of the socket extend from the recess to the fixed contact washer g, so as to maintain the nut with the grooves Z and Z coincident while inserting the nut and connecting the screw it therewith. The socket is expanded slightly toward the recess and is made a little larger than the nut at the bottom to facilitate the introduction of the nut or its removal from the socket.

The square form of the nut and socket forms an engagement which prevents the nut from turning when the screw it is rotated; but any other form to secure such engagement would obviously serve the same purpose.

The eye upon the outer end of the fuse wire is bent over the head of the connector and the screw j inserted to clamp it thereto.

A cap m is shown applied to the larger end of the body, and by the construction provements contributes to the efficiency and durability of the device, while making it safe in its operation and convenient to renew the fuse.

I am aware that it is common to employ in such a fuse plug a central contact located like the screw it in my construction, and to employ the connector made of thin sheet metal which I have referred to above, and I do not therefore claim such features broadly, as my invention consists in the par ticular modifications which I have made in providing the stationary bushing in the bot tom of the plug, the square socket extending from such bushing all the way to the recess in which the fingers may insert a nut, and in forming the connector k with a thickened and elongated head to secure a strong threaded connection for the clamping screw Having thus set forth the nature of the invention what is claimed herein is:

1. A fuse plug having a hollow insulating body with a contact bushing in one end, a flange upon one end of the bushing and awasher clenched upon the opposite end securing it permanently in place, a screw shell upon the same end of the body as the bushing, a s uare socket extended from the bushing to t e recess to maintain the relation of a nut therewith, and a clamping nut fitted removably therein, a contact screw extended through the bushing to hold the nut, a connector .extended from the exterior shell through the wall of the body into the said socket, and a fuse wire clamped to such connector and to the bushing by screws, as shown and described.

2. A fuse lug having a hollow insulating body reduced at one end and provided with a contact shell, the body recessed in its larger end to insert the fuse wire freely, a square socket extended from the recess toward the smaller end of the body to maintain the relation of a nut therewith and a nut fitted removably therein and such socket and nut engaged to prevent the nut from turning durlng its insertion, a central contact screw for clamping the nut in the socket, a connector embedded in the wall of the body and ex tended from the shell to the interior of the recess, and having a thickened and elongated head with a tap-hole extended into the same, a clamp screw in the tap-hole, and a fuse wire extended from such thickened head of the connector to the under side of the nut.

3. A fuse plug as described in claim 2, and the outside of the nut and the inside of the socket having corresponding grooves to clear the fuse wire.

4;. A fuse plug having a hollow insulating body with a contact bushing in one end, a flange upon one end of the bushing and a washer clenched upon the opposite end securing it permanently in place, a screw shell upon the same end of the body as the bushing, a square socket extended from the bushing to the recess to guide the insertion of a nut, and a clamping nut fitted removably therein, a contact screw extended through the bushing to hold the nut, a connector embedded in the wall of the body and extended from the shell into the socket, and having a thickened and elongated head with a taphole extending longltudinally in the same, a clamp screw in the tap-hole, and a fuse wire extended from such thickened head of the connector to the under side of the nut.

In testimony whereof I have hereto set my hand.

KARL B. SHULZ. 

